I launched the TE, loaded the RP settings, and the computer experience is set to default, linked to the game's difficulty level. Since we were playing on 160% difficulty, the computer experience is set to Expert accordingly. In the VT settings, this was removed, and now, it seems, the experience is always set to Impossible.

Expert (computer gains experience faster) Experience gain rate for computer heroes' soldiers and garrisons: EXPERT GAME DIFFICULTY (COMPUTER EXPERIENCE GAIN RATE) - EXPERT
Option 229-4 [author: Timothy Pulver] (script00)
Experience gain rate for computer heroes' soldiers and garrisons:
EXPERT
Coefficient for computer heroes: 400%
Coefficient for garrisons: x75
Additional computer experience: +300

Difficult (computer gains experience quickly) Experience gain rate for computer heroes' soldiers and garrisons: DIFFICULT GAME DIFFICULTY (COMPUTER EXPERIENCE GAIN RATE) - DIFFICULT
Option 229-3 [author: Timothy Pulver] (script00)
Experience gain rate for computer heroes' soldiers and garrisons:
DIFFICULT
Coefficient for computer heroes: 300%
Coefficient for garrisons: x50
Additional computer experience: +200 0